PARIS – In recent years, it hasn’t been very common for two American men to face off in the second round of Roland Garros, traditionally the toughest Grand Slam for U.S. players.

But it’s been a fine start for the U.S. in 2013. Qualifying saw a number of Americans advance to the main draw, and the U.S. women had a breakout Day 1. On Monday it was the men’s turn, with No. 19 John Isner and 21-year-old Ryan Harrison advancing to set up a second-round match between the two buddies on Wednesday.

The women also continued their strong start on Day 2, as Sloane Stephens, Varvara Lepchenko, Bethanie Mattek-Sands, Vania King and Melanie Oudin all came through.

But while the majority of the women in action were expected to win, Isner and Harrison have struggled on red European clay this season. Isner, in particular, was extremely excited after his match, rebounding from a break down in the third set to advance and pumping his fist like a madman after the contest.

"That's the way I got to play," he said. "No matter what round it is, no matter what tournament I'm playing, if I'm playing with a lot of enthusiasm and confidence like that, normally it bodes well for me. So [I was] trying to get that going here. Thought I played a good match today. I think toward the end those fist pumps were warranted because I was able to close this match out in straight sets."

Isner had high hopes coming into the season, but he suffered a bone bruise on his right knee while training in December that gradually grew worse. After he hobbled around in a loss to Harrison in Sydney, he pulled out of the Australian Open. It took him a good two months after that to get his groove back.

"Mentally it took a toll on me," said Isner, who captured the U.S. Clay Court Championship in Houston in April, beating two excellent clay courters in Juan Monaco and Nicolas Almagro to win the title. "I feel like I pressed a little bit too much. Felt like I fell behind the rest of my competitors not being able to play in Australia. But that's the wrong way to go about it, so I know that in the future if it happens to come up. But I've turned the corner from that and I'm playing well and I feel strong and nothing is bothering me."

Harrison, meanwhile, had a fine Australian summer but struggled from February until mid-May, when he won the Savannah Challenger on green clay. The victory provided a boost of confidence, and Harrison entered Roland Garros with high hopes.

"I'm super excited to be here and ready to give everything I have to make a run," he said.

Isner and Harrison grew close at Davis Cup, and they frequently kid with each other on Twitter. They both have the same major weapon, their serve, and both hail from the South. Isner has a bigger forehand, Harrison a better backhand, and both volley fairly well, although Harrison has been more reticent to come to the net. Both guys are working on becoming more aggressive returners.

The two not only faced off in Sydney this year but also in the first round of Houston, a tight victory for Isner.

"He's a very athletic guy," Isner said. "I think his speed is a bit underrated. He has a very good serve. He's not really tall or anything, but his serve is very, very good. I think his best shot is his second serve. He goes after that a lot, and he makes it a lot, and he's very confident with that shot. So it's going to be one of those where we're both going to have to try to take care of our serves and see what happens after that."

Said Harrison of squaring off against Isner, "I’m going to have to serve well. John is one of the most difficult guys to break on tour, and if I'm not serving well, it will be a rough day. John has proved in the past that he is very capable of playing some of his best tennis on clay. I'm going to have to play well."

It would be better for U.S. tennis if the two bangers met some time in the second week, but that’s not the luck of the draw. But there is a silver lining: there will be a U.S. man still alive on Friday.

"I would probably rather not play Ryan," Isner said. "It's tough playing your good friend, especially at a Grand Slam. But I guess one good thing is that we're guaranteed to have an American into the third round."